The present invention relates to an apparatus for dividing a suspension of fibrous cellulose pulp into a plurality of portions in a closed housing having inlet and outlet means.
In the production of fibrous cellulose pulp impurities are supplied from outside as well as through deficiencies during the actual manufacturing process. These undesired parts may vary in size and consist for instance of sand particles, gravel, stones, nuts, parts of welding electrodes and pieces of metal. It is therefore necessary to remove such undesired parts, especially from suspensions which are to be processed further in machines and equipments which are sensitive and may be damaged by such solid parts, or which for other reasons must as far as possible be freed from impurities. Various types of devices have been suggested for separating undesired solid parts from a fibrous cellulose pulp, see e.g. Pat. specifications No. SE 7903032-6 (corresponding to U.S. Pat. No. 4,303,508), SE 8503372-8 (corresponding to U.S. Pat. application No. 882,716) and U.S. Pat. No. 4,231,881.
In order to be able to subject a fibrous cellulose pulp of medium concentration, i.e. about 6-15%, a screening operation, a screening device must be used which generates pulsations and shearing forces in the pulp so that it is fluidized, i.e. it is transferred to an easy flowing condition, and the fibres can then move in relation to each other. A part-flow of finer fibrous material (accept) and a part-flow of coarser material (reject) can thus be obtained through screening. A screening device based on the above principle is described in SE 8501030-4 (corresponding to U.S. Pat. application No. 836 123).